Major changes began taking place as Emory Coblentz continued his reconstruction of the Frederick Railroad system. Orders for newer, larger trolleys began to be placed but his vision involved more than the railroad.
By 1913, the Frederick Railroad and the Hagerstown Railway companies had been in negotiations to construct a larger and more modern power plant that would serve both companies. Together they formed the Frederick and Hagerstown Power Company to construct a brick powerhouse at Security, MD near Hagerstown. By the time construction began the two rail companies themselves had merged into the Hagerstown and Frederick Railway Company.
Despite the merger the two ends of the system continued to run with little changes to their operations, but could more easily share equipment. In 1917, a fire leveled the carbarn at Summit & Howard Streets in Hagerstown destroying nearly all of the trolleys based out of Hagerstown. A series of new "Nearside" city trolleys were purchased as well as the first two steel sided interurban cars that would become the company signature. With the success of #168 and #169, three more near-identical cars were purchased with the last being delivered in 1921. the five "168 series" cars would be seen on branch line and main line alike.
Coblentz's focus however was not on the trolleys but rather the power, and spent the decade buying up power companies and other trolley systems in the region to integrate into the Hagerstown & Frederick Railway's power grid. A sign of things to come.